Non-regulatory airspace surrounding designated Class C airspace airports wherein ATC provides radar vectoring and sequencing on a full-time basis for all IFR and participating VFR aircraft. The service provided in the outer area is called Class C service which includes IFR/IFR separation; IFR/VFR traffic advisories and conflict resolution; and VFR/VFR traffic advisories and, as appropriate, safety alerts. The normal radius will be 20 nautical miles with some variations based on site-specific requirements.

Source FAA Pilot/Controller Glossary↗ · checked 2026-08-25